This invention relates to sheets for sublimation transfer recording.
In office automation terminals such as facsimiles, printers, copying machines etc. which have lately been rapidly spread, there has been an increasing demand for color recording having a capacity for a great amount of information and also being visually preferable. On the other hand, the development of techniques of color recording of television images has been sought.
Currently, for these purposes, color recording techniques by electron photography, an ink-jet process, a heat-sensitive transfer recording process etc. have been under study. Of those, the heat-sensitive transfer recording process is considered a more advantageous process as compared with other processes since the maintenance and operation of the device are easier and the device and enpendable supplies are less expensive.
The heat-sensitive transfer recording process is a process which comprises overlapping a sheet-formed base coated with an ink containing a dye with an image receiving body with its ink-coated surface inside and thereafter heating the back surface of the ink-coated surface of the base by a heat-sensitive head to transfer the dye on the base to the image receiving body.
The heat-sensitive transfer recording process is roughly classified into two modes, i.e., a molten transfer process which comprises using a recording sheet composed of a base coated with a heat-melt ink and a sublimation transfer process which comprises using a recording sheet coated with an ink containing a sublimable dye, and the latter is more advantageous in particular for full color recording since it is possible to control the amount of the dye to be sublimed and transferred by controlling the energy applied to a heat-sensitive head and hence gradation expression is easy.
2. Description of the Prior Art
In general, since the temperature of the heat-sensitive head on transfer recording reaches 200.degree. C. or higher, where a conventional recording sheet was used, there were such problems that a binder resin on the recording sheet softened or melted by heat, and the recording sheet and an image receiving body were adhered to each other and hence release after recording was difficult, that the binder resin was transferred to the image receiving body together with the dye and thus gradation expression was impossible, etc.
Further, on transfer recording, since the recording sheet and the image receiving body were overlapped and forwarded together, there was, for example, such problem that by abrasion of the contacted surfaces of both, a phenomenon of abrasion staining was brought about, that is, the non-printed part of the receiving body was stained, and so forth.
Therefore, as a method of preventing adhesion of the recording sheet and the image receiving body, there have been proposed methods of improving heat resistance by employing crosslinkable resins as a binder resin for the recording sheet and a resin for the image receiving body (Japanese patent application Laid-open No. 215397/1983, Japanese patent aplication Laid-open No. 212994/1983 and Japanese patent application Laid-open No. 215398/1983).